Compiler Plugin - Create verification Pool

[Daniel-Pfeffer]

Add a dynamically created pool of classes that can be used for verification.
E.g.: A Program uses NotNegativeVerifier and NotPositiveVerifier, the ClassPool then creates fields for both verifier like

object VerifierPool{
    val notNegativeVerifier = NotNegativeVerifier()
    val notPositiveVerifier = NotNegativeVerifier()
}

As all verifier must be statless we can use a pool to reuse verifier instances, to not waste performance